One of the more versatile tools used by mechanics and the like is the ratchet wrench. As is known, ratchet wrenches include a handle and a working head. Some ratchet wrenches directly engage a work piece, such as a nut or bolt head. Other ratchet wrenches have a drive stud projecting from a rotatable drive member, also sometimes referred to as a ratchet wheel. This drive stud is typically integral with the drive member. A ratchet mechanism selectively engages the drive member to permit rotation of the drive member in one direction while preventing rotation in a second, opposite rotational direction. The ratchet mechanism is actuable so as to selectively permit rotation of the drive member in either a clockwise or counterclockwise direction. Usually, a lever is provided on the working head to allow the user to select the desired rotation of the drive stud.
The drive stud, in turn, receives a selected one of a plurality of sockets, socket adapters, extenders, and the like, which may be referred to as a work piece that engages the nut or bolt head. A socket, for example, has an opening sized and adapted to receive the drive stud. A second opening is located oppositely of the drive stud opening with this second opening having teeth and an opening sized to receive a nut, bolt head and the like. A set of such sockets is usually provided allowing the user to interchange sockets for differently sized nuts and bolts. Adapters and extenders have an opening to receive the drive stud and an opposite drive stud to receive a socket or other piece.
One disadvantage of existing ratchet wrenches is that, typically, portions of the operative mechanism project through the upper surface of the working head. These protruding mechanical elements act to increase the effective thickness of the working head. In addition, they can sometimes interfere with the use of the wrench, especially in confined spaces. Moreover, the protruding elements clutter the working head upper surface and do not permit the upper surface to receive identifying logos or other designations of desired size.
The drive stud on the working or “ratchet head” also often employs a ball detent to retain the selected socket, adapter or extender on the drive stud. To remove the socket, the user typically grips the head of the wrench in one hand and the socket in the other in order to separate the socket from the wrench head. Sometimes, removal of the socket from the drive stud is difficult. This can arise should dirt effect the actuation of the ball detent. Other times, should the user's hands be oily or greasy, it is difficult to obtain sufficient grip on the cylindrical socket in order to effect separation. Indeed, small variations due to manufacturing tolerances can exacerbate the difficulty of removal of the socket, adapter, extender, etc.
In order to ease the procedure of removing a socket from the drive stud, it is known to provide ratchet wrenches with a “quick release” mechanism. An early example of a quick release mechanism is disclosed in U.S. Pat. No. 3,208,318 issued Sep. 28, 1965 to Roberts. Here, the detent ball interacts with a cavity on a release pin which is axially disposed in the drive stud and is reciprocal in the longitudinal direction. The release pin has a head that protrudes from the wrench, opposite the drive stud, to provide a button whereby a user can depress the release pin against the force of a return spring. Depressing the release pin moves the cavity into registration with the detent ball so that there is no spring actuated force on the detent ball allowing the socket to be easily removed. When released, the release pin is biased so that it presses against the detent ball thereby retaining the socket on the drive stud. Another example of a quick release mechanism is disclosed in U.S. Pat. No. 4,420,995 issued Dec. 20, 1983 to Roberts. Here, the reciprocating release pin is rotatable to provide a positive locking structure for the detent ball.
While the above-described mechanisms are reliable and effective in use, the possibility exists that, under some conditions, a user may inadvertently depress the release pin while using the wrench. This can happen, for example, if the head of the wrench is placed in the palm of the users hand since the hand can come in contact with the button or head of the release pin and can inadvertently depress the same while the wrench is used thereby inadvertently releasing the socket.
In order to overcome these drawbacks, a slide actuator for the release pin is disclosed in U.S. Pat. No. 6,109,140 issued Aug. 29, 2000 to Roberts et al. In this structure, the head of the release pin is not exposed exteriorly of the working head. Rather, a slide actuator projects upwardly from the drive head directly above the release pin and reciprocates in a direction transverse to the rotational axis of the drive stud and thus the longitudinal axis of the release pin. The slide actuator has a ramp face which attacks the head of the release pin so that reciprocation of the slide actuator acts to depress or release the release pin.
Again, the structure disclosed in the '140 patent is generally reliable and effective. However, the slide actuator requires that the user adjust his/her grip on the handle or use his/her other hand while gripping the wrench in order to employ the quick release. In addition, the wrench disclosed in the '140 patent has the ratchet reversing lever located on the head of the wrench which results in multiple mechanisms presenting a cluttered appearance for the head. In addition, since the slide actuator projects upwardly from the working head, it can interfere with using the wrench in confined spaces.
Accordingly, there remains a need for improved ratchet wrenches having a more streamlined appearance including generally flat and generally uninterrupted upper surfaces. A need exists, also, for ratchet wrenches that incorporate improved quick release mechanisms for the sockets used therewith. There is a need for ratchet wrenches that have pawl control release mechanisms that are convenient and more accessible to the user. There is a further need for quick release mechanisms having simplified structure. There is also a need for ratchet wrenches having quick release mechanisms wherein the working head has a reduced profile.